Effects of synthetic thymosin-alpha 1 and its analogs on fertilizability of human sperm: search for a biologically active, stable epitope.

Naz RK, Kaplan P, Badamchian M, Goldstein AL

Archives of andrology1 Jul 1995Cited by 3 (Europe PMC)

PMID8554434DOI10.3109/01485019508987855PepBankPUB-08554434

Publisher page PubMedAsk about this study

Summary

The text of this summary is not shown here, because the article license does not allow reuse. Read it at the source (opens in a new tab)

Text rights: Publisher copyright. Results still quote short attributed sentences.

Results from this study6

1 result from studies that gave the peptide. No result from this study comes from people.

01LabEx vivo tissueEfficacy outcome
In human sperm, thymosin alpha‑1 significantly increased penetration rates in the sperm penetration assay, with the strongest effect at 0.5 microgram/100 microL.
In plain wordsIn lab tests with human sperm, thymosin alpha‑1 raised sperm penetration rates, most strongly at 0.5 microgram per 100 microlitres.
Peptide
Thymosin alpha-1
Outcome
IncreaseSperm penetration rate in SPA
Study
humann: not reported in source
Human sperm penetration assay
Outcome group
Sex hormones and fertility · Reproductive and sexual health
Studied dose
Strongest effect at 0.5 microgram/100 microLAs given in this study (human).
Measurements
Strongest enhancing concentration
0.5 microgram/100 microL
human sperm
Source sentences
Summary
T alpha 1 significantly (p < .0001) increased the penetration rates in SPA, with the strongest enhancing effect at 0.5 microgram/100 microL concentration.
1 context sentence(design, population, supporting numbers)
Summary · context
T alpha 1 and these six analogs were tested for their effects on human sperm penetration rates in the sperm penetration assay (SPA).
Report a problemFND-0855443401

Studies that did not test the peptide alone5

In this study, Thymosin alpha-1 was a lab tool or a carrier, part of a mix, or the subject of a lab method. These results are not evidence about taking Thymosin alpha-1.

02LabNot a test of Thymosin alpha-1 aloneEx vivo tissueEfficacy outcome
In human sperm, of six thymosin alpha‑1 analogs only T alpha 1-Gly-NH2 and T alpha 1-C14 retained the enhancing effect on penetration in the sperm penetration assay.
In plain wordsIn lab tests with human sperm, only two of six thymosin alpha‑1 analogs kept the sperm-penetration boost.
Peptide
Thymosin alpha-1
Outcome
MixedAnalog enhancement of sperm penetration
Study
humann: not reported in source
Human sperm penetration assay
Outcome group
Sex hormones and fertility · Reproductive and sexual health
Source sentences
Summary
Of the six analogs tested only two, T alpha 1-Gly-NH2 and T alpha 1-C14, retained the enhancing effects in SPA.
1 context sentence(design, population, supporting numbers)
Summary · context
T alpha 1 and these six analogs were tested for their effects on human sperm penetration rates in the sperm penetration assay (SPA).
In this study, Thymosin alpha-1 was a lab tool or a carrier, part of a mix, or the subject of a lab method. This result is not evidence about taking Thymosin alpha-1.
Report a problemFND-0855443402
03LabNot a test of Thymosin alpha-1 aloneEx vivo tissueSafety outcome
In human sperm, none of the six thymosin alpha‑1 analogs decreased penetration rates or affected sperm motility compared with control.
In plain wordsIn lab tests with human sperm, none of the six analogs lowered sperm penetration or changed sperm motility compared with control.
Peptide
Thymosin alpha-1
Outcome
No significant changeAnalog effect on penetration decrease or sperm motility
Study
humann: not reported in source
Human sperm penetration assay
Comparator
Control
Outcome group
Sex hormones and fertility · Reproductive and sexual health
Source sentences
Summary
None of the analogs decreased the penetration rates or affected sperm motility compared to control.
1 context sentence(design, population, supporting numbers)
Summary · context
T alpha 1 and these six analogs were tested for their effects on human sperm penetration rates in the sperm penetration assay (SPA).
In this study, Thymosin alpha-1 was a lab tool or a carrier, part of a mix, or the subject of a lab method. This result is not evidence about taking Thymosin alpha-1.
Report a problemFND-0855443403
04LabNot a test of Thymosin alpha-1 aloneEx vivo tissueMechanism
In human sperm, the enhancing activity of thymosin alpha‑1 resides primarily in the C-terminal 14 amino acids.
In plain wordsIn lab tests with human sperm, the last 14 amino acids of thymosin alpha‑1 carry most of its sperm-boosting activity.
Peptide
Thymosin alpha-1
Outcome
Not applicableActive epitope of T alpha 1
Study
humann: not reported in source
Human sperm penetration assay
Outcome group
Sex hormones and fertility · Reproductive and sexual health
Source sentences
Summary
The enhancing activity resides primarily in an epitope, the C-terminal 14 amino acids of T alpha 1.
1 context sentence(design, population, supporting numbers)
Summary · context
T alpha 1 and these six analogs were tested for their effects on human sperm penetration rates in the sperm penetration assay (SPA).
In this study, Thymosin alpha-1 was a lab tool or a carrier, part of a mix, or the subject of a lab method. This result is not evidence about taking Thymosin alpha-1.
Report a problemFND-0855443404
05LabNot a test of Thymosin alpha-1 aloneEx vivo tissueEfficacy outcome
In human sperm, the C-terminally protected T alpha 1-Gly-NH2 analog was as potent as intact thymosin alpha‑1.
In plain wordsIn lab tests with human sperm, the Gly-NH2 analog worked as well as intact thymosin alpha‑1.
Peptide
Thymosin alpha-1
Outcome
No significant changePotency of T alpha 1-Gly-NH2 analog
Study
humann: not reported in source
Human sperm penetration assay
Comparator
Intact T alpha 1
Outcome group
Sex hormones and fertility · Reproductive and sexual health
Source sentences
Summary
The T alpha 1-Gly-NH2 analog that had its C-terminal protected was as potent as the intact T alpha 1 peptide.
1 context sentence(design, population, supporting numbers)
Summary · context
T alpha 1 and these six analogs were tested for their effects on human sperm penetration rates in the sperm penetration assay (SPA).
In this study, Thymosin alpha-1 was a lab tool or a carrier, part of a mix, or the subject of a lab method. This result is not evidence about taking Thymosin alpha-1.
Report a problemFND-0855443405
06LabNot a test of Thymosin alpha-1 aloneEx vivo tissueMechanism
In human sperm, maximal enhancement of sperm penetration by thymosin alpha‑1 analogs needed both the N-terminal serine and the C-terminal asparagine to be intact and unmodified.
In plain wordsIn lab tests with human sperm, the sperm-boosting effect needed both ends of the thymosin alpha‑1 peptide to stay unchanged.
Peptide
Thymosin alpha-1
Outcome
Not applicableTerminal amino acid requirement for T alpha 1 analog activity
Study
humann: not reported in source
Human sperm penetration assay
Outcome group
Receptor activity and mechanism · Reproductive and sexual health
Source sentences
Summary
However, for maximal effect both N- and C-terminal amino acids (serine and asparagine, respectively) have to be intact and unmodified.
In this study, Thymosin alpha-1 was a lab tool or a carrier, part of a mix, or the subject of a lab method. This result is not evidence about taking Thymosin alpha-1.
Report a problemFND-0855443406

AI wrote and checked these results. AI can make mistakes, so check important results against the source.

Version history

PepBank keeps every version of the data on this study. Status changes from Retraction Watch, Europe PMC and Crossref are listed with their source.

Version 3Current
10 Oct 2026, 08:55 UTC
Study results updated
Version 2
9 Oct 2026, 03:03 UTC
Study data updated · source update from Europe PMC
Version 1
9 Oct 2026, 03:02 UTC
First added · source update from Europe PMC

Subjects

Terms as the source lists them.

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